Stabilized monomer dispersion containing inorganic oxide nanoparticles with high refractive index and its preparation

Abstract

The present invention relates to a stabilized monomer dispersion containing inorganic oxide nanoparticles with high refractive index in which the refractive index of the inorganic oxide nanoparticles is greater than 1.65 and the average particle size of the high refractive inorganic oxide nanoparticles ranges from 1 to 100 nm and its content is in a range of from 1.0% by weight to 10.0% by weight based on the total weight of the monomer dispersion. The present invention also relates to a process for preparing the stabilized monomer dispersion containing high refractive inorganic oxide nanoparticles.

What is claimed is: 
     
       1. A process for preparing a stabilized monomer dispersion containing inorganic oxide nanoparticles with a high refractive index greater than 1.65, the process comprising the steps of:
 condensing and then hydrolyzing an alkoxide precursor corresponding to the inorganic oxide in a reactive monomer serving as a solvent in the presence of an chelating agent and water at a temperature of from 0 to 50° C. to produce a dispersion consisting of the monomer and inorganic oxide nanoparticles dispersed therein, wherein an equivalent ratio of the water to the alkoxide is equal to or less than 3, and an equivalent ratio of the chelating agent to the alkoxide is at least 2. 
 
     
     
       2. The process of  claim 1 , wherein the inorganic oxide nanoparticles are selected from the group consisting of titanium dioxide, zirconium dioxide, and cerium dioxide. 
     
     
       3. The process of  claim 1 , wherein the alkoxide precursor is represented by X(OR) 4 , wherein R's are the same or different and represent a straight or branched alkyl group having 1 to 8 carbon atoms, and X is Ti, Zr, or Ce. 
     
     
       4. The process of  claim 3 , wherein the alkoxide is titanium tetraisopropoxide or titanium tetrabutoxide. 
     
     
       5. The process of  claim 3 , wherein the alkoxide is zirconium tetraethoxide or zirconium tetrapropoxide. 
     
     
       6. The process of  claim 1 , wherein the chelating agent is a compound having a carboxyl (—COON) functional group. 
     
     
       7. The process of  claim 6 , wherein the chelating agent is acetic acid, citric acid, acrylic acid, or methacrylic acid.